Vita Sackville-West loved to see her plants doing their own thing. Her roses would tumble over walls and borders and lazily spill into paths and lawns.

While husband Harold Nicholson designed the garden at Sissinghurst Castle with straight lines and symmetry, Vita’s extravagant, romantic planting blurred the severity to make it one of the most successful gardens in the last 100 years.

Dan Cooper, too, plants from the heart and with a touch of the Sackville-West rebellion.

Despite restricted space and some serious hard landscaping, his garden at the Watch House, in Broadstairs, has a profusion of tropical plants that burst skywards.

Dan pushes the boundaries every which way; rare exotic specimens jostle for pride of place, temperate Geranium maderense defies the British climate and shelters in the narrow entrance while, it seems, pots packed with black rose succulents, purple bell vines and lilac fuchsias encroach on every spare inch of space when Dan’s back is turned.

Agapanthus africanus create a sea of blue while a 10ft tower of powder-blue jewels, the Echium pininana, leans into the frame against a mass of glossy foliage which gives the garden its jungle jangle.

Bees bounce from the Echium’s giant spikes, loving the slightly hairy and star-like flowers, to the smaller Echium wildpretti.

The Ethiopian lily (Zantedeschia aethiopica) and Osteospermum Nuanza Copper Purple join a backing group almost singing with zingy oranges, reds and plummy blooms from Tenerife to Tasmania.

The devil is in the detail – a rare Digitalis sceptrum, in burnt orange with blood-like veins adds more drama and is one of Dan’s favourites.

He said: “I like a challenge. A challenge to source and grow rare or exotic plants. There are probably only a couple of these sceptrums growing outside in this country. Growing up in Cornwall, where the climate allows for temperate plants has meant I have always been attracted to tropical and exotic plants.”

When Dan and his partner Alex bought the Watch House in 2006, it had ‘no redeeming features’. There was a muddle of outbuildings and a few past-their-sell-by-date leggy shrubs.

After two years of vain attempts to bring the garden up to scratch the couple realised drastic action was needed to transform the garden if it was ever to become a beautiful outside living space. In came the mini-digger and nothing except the outer brick walls escaped demolition.

A designer was hired to help Dan and Alex work out the logistics of creating a contemporary garden next to The Watch House, once two fishermen’s cottages with a smokery in the undercroft.

Dan, who has a degree in Landscape Management but went on to be a buyer at John Lewis, said: “In many ways this is more of a roof garden as we had to consider the weight being put on the old basement smokery.”

Large slate tiles make for a smart base, generous L-shaped raised beds wrap round the rear and side walls with weatherboarding above painted in Farrow & Ball’s Verte de Terre, adding a sophisticated twist to a traditional Kentish theme.

A bespoke outside kitchen, complete with granite work top, barbecue cooker, cupboards and lighting was built by a local carpenter and finished in the same soft green-grey paintwork. The kitchen is as much a talking point as the planting. The sheltered sanctuary did not escape last winter’s high winds, however. The three quite slim trees ‘took a bashing’ and it is on Dan’s list to give them some serious surgery at the end of this season.

That certainly will not happen until flowers on the Santa Cruz Ironwood (Lyonothamus floribundus ssp asplenifolius) are over. It is the first time the elegant tree has produced white achillea-shaped heads that look rather like spinning plates.

Dan said: “The tree has really grown far too tall but I am not going to do anything until the autumn. It does give a lovely, dappled shade and screens neighbouring houses. I am very excited by seeing the first flowers.”

And exciting it is. This is a garden with a joie de vivre and a barrowful of style that National Garden Scheme visitors will savour.

Dan, who runs the Frustrated Gardener website, said: “We had not planned to open our garden. We were badgered into it, quite forcefully! We are now looking forward to inviting the public into our sanctuary and hope they get some ideas for their own gardens.”

The Watch House demonstrates it is possible to create an exceptional garden in a small space but it requires time, a passion, a knowledge of plants – and the roots of rebellion.

FACTFILE

The Watch House is at 7 Thanet Road, Broadstairs CT10 1LF. It is open noon to 4pm on Saturday, August 2 and Sunday, August 3. Well-behaved adults, children and dogs welcome. Admission £3. Visitors should use the car park at the top of Thanet Road or others around the town.

More info at Dan’s website thefrustratedgardener.com and ngs.org.uk

Also open this weekend as part of the NGS

Bexon Manor, Hawks Hill Lane, Bredgar ME9 8HE
Two-acre garden, divided into a series of rooms. Rose-covered gazebo, water feature plus a five-acre woodland walk.
Open: Sunday

Eureka, Buckhurst Road, Westerham Hill TN16 2HR
Another NGS first for 2014. Includes a children’s treasure trail and viewing platform.
Open: Saturday and Sunday

Knowle Hill Farm, Ulcombe, near Maidstone ME17 1ES
Don’t miss the spectacular views from this 1.5-acre garden that’s packed with many unusual plants.
Open: Sunday

Leydens, Hartfield Road, Edenbridge TN8 5NH
Small private garden of garden designer, nursery owner, author and former gold winner at the Chelsea Flower Show. Open: Sunday

Old Buckhurst, Markbeech, near Edenbridge TN8 5PH
Partly-walled cottage garden around a 15th-century Grade II listed farmhouse. Open: Sunday

Rose Farm Studio, Rose Farm Road, Pluckley TN27 0RG
An artist’s garden. Many potted plants, roof meadow, wild flower meadow and a pebble-dashed Morris Minor!
Open: Saturday and Sunday